tsai
/
ImageSharp
mirror of https://github.com/SixLabors/ImageSharp
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

Add additional YCbCr subsample rates

pull/1734/head
Brian Popow 5 years ago
parent
5834e4fb53
commit
b506e92479
8 changed files with 94 additions and 10 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 35
      src/ImageSharp/Formats/Jpeg/JpegColorType.cs
  2. 29
      src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs
  3. 5
      tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.Metadata.cs
  4. 23
      tests/ImageSharp.Tests/Formats/Jpg/JpegEncoderTests.cs
  5. 3
      tests/ImageSharp.Tests/TestImages.cs
  6. 3
      tests/Images/Input/Jpg/baseline/jpeg410.jpg
  7. 3
      tests/Images/Input/Jpg/baseline/jpeg411.jpg
  8. 3
      tests/Images/Input/Jpg/baseline/jpeg422.jpg

35
src/ImageSharp/Formats/Jpeg/JpegColorType.cs
View File

@ -22,14 +22,45 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
/// </summary>
YCbCrRatio444 = 1,
/// <summary>
/// YCbCr (luminance, blue chroma, red chroma) color as defined in the ITU-T T.871 specification.
/// The two chroma components are sampled at half the horizontal sample rate of luma while vertically it has full resolution.
///
/// Note: Not supported by the encoder.
/// </summary>
YCbCrRatio422 = 2,
/// <summary>
/// YCbCr (luminance, blue chroma, red chroma) color as defined in the ITU-T T.871 specification.
/// In 4:1:1 chroma subsampling, the horizontal color resolution is quartered.
///
/// Note: Not supported by the encoder.
/// </summary>
YCbCrRatio411 = 3,
/// <summary>
/// YCbCr (luminance, blue chroma, red chroma) color as defined in the ITU-T T.871 specification.
/// This ratio uses half of the vertical and one-fourth the horizontal color resolutions.
///
/// Note: Not supported by the encoder.
/// </summary>
YCbCrRatio410 = 4,
/// <summary>
/// Single channel, luminance.
/// </summary>
Luminance = 2,
Luminance = 5,
/// <summary>
/// The pixel data will be preserved as RGB without any sub sampling.
/// </summary>
Rgb = 3,
Rgb = 6,
/// <summary>
/// CMYK colorspace (cyan, magenta, yellow, and key black) intended for printing.
///
/// Note: Not supported by the encoder.
/// </summary>
Cmyk = 7,
}
}

29
src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs
View File

@ -457,8 +457,10 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
{
case JpegColorSpace.Grayscale:
return JpegColorType.Luminance;
case JpegColorSpace.RGB:
return JpegColorType.Rgb;
case JpegColorSpace.YCbCr:
if (this.Frame.Components[0].HorizontalSamplingFactor == 1 && this.Frame.Components[0].VerticalSamplingFactor == 1 &&
this.Frame.Components[1].HorizontalSamplingFactor == 1 && this.Frame.Components[1].VerticalSamplingFactor == 1 &&
@ -466,11 +468,38 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
{
return JpegColorType.YCbCrRatio444;
}
else if (this.Frame.Components[0].HorizontalSamplingFactor == 2 && this.Frame.Components[0].VerticalSamplingFactor == 2 &&
this.Frame.Components[1].HorizontalSamplingFactor == 1 && this.Frame.Components[1].VerticalSamplingFactor == 1 &&
this.Frame.Components[2].HorizontalSamplingFactor == 1 && this.Frame.Components[2].VerticalSamplingFactor == 1)
{
return JpegColorType.YCbCrRatio420;
}
else if (this.Frame.Components[0].HorizontalSamplingFactor == 1 && this.Frame.Components[0].VerticalSamplingFactor == 1 &&
this.Frame.Components[1].HorizontalSamplingFactor == 1 && this.Frame.Components[1].VerticalSamplingFactor == 2 &&
this.Frame.Components[2].HorizontalSamplingFactor == 1 && this.Frame.Components[2].VerticalSamplingFactor == 2)
{
return JpegColorType.YCbCrRatio422;
}
else if (this.Frame.Components[0].HorizontalSamplingFactor == 4 && this.Frame.Components[0].VerticalSamplingFactor == 1 &&
this.Frame.Components[1].HorizontalSamplingFactor == 1 && this.Frame.Components[1].VerticalSamplingFactor == 1 &&
this.Frame.Components[2].HorizontalSamplingFactor == 1 && this.Frame.Components[2].VerticalSamplingFactor == 1)
{
return JpegColorType.YCbCrRatio411;
}
else if (this.Frame.Components[0].HorizontalSamplingFactor == 4 && this.Frame.Components[0].VerticalSamplingFactor == 2 &&
this.Frame.Components[1].HorizontalSamplingFactor == 1 && this.Frame.Components[1].VerticalSamplingFactor == 1 &&
this.Frame.Components[2].HorizontalSamplingFactor == 1 && this.Frame.Components[2].VerticalSamplingFactor == 1)
{
return JpegColorType.YCbCrRatio410;
}
else
{
return JpegColorType.YCbCrRatio420;
}
case JpegColorSpace.Cmyk:
return JpegColorType.Cmyk;
default:
return JpegColorType.YCbCrRatio420;
}

5
tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.Metadata.cs
View File

@ -143,6 +143,10 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
[InlineData(TestImages.Jpeg.Baseline.Jpeg420Small, JpegColorType.YCbCrRatio420)]
[InlineData(TestImages.Jpeg.Baseline.Jpeg444, JpegColorType.YCbCrRatio444)]
[InlineData(TestImages.Jpeg.Baseline.JpegRgb, JpegColorType.Rgb)]
[InlineData(TestImages.Jpeg.Baseline.Cmyk, JpegColorType.Cmyk)]
[InlineData(TestImages.Jpeg.Baseline.Jpeg410, JpegColorType.YCbCrRatio410)]
[InlineData(TestImages.Jpeg.Baseline.Jpeg422, JpegColorType.YCbCrRatio422)]
[InlineData(TestImages.Jpeg.Baseline.Jpeg411, JpegColorType.YCbCrRatio411)]
public void Identify_DetectsCorrectColorType(string imagePath, JpegColorType expectedColorType)
{
var testFile = TestFile.Create(imagePath);
@ -159,6 +163,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
[WithFile(TestImages.Jpeg.Baseline.Jpeg420Small, PixelTypes.Rgba32, JpegColorType.YCbCrRatio420)]
[WithFile(TestImages.Jpeg.Baseline.Jpeg444, PixelTypes.Rgba32, JpegColorType.YCbCrRatio444)]
[WithFile(TestImages.Jpeg.Baseline.JpegRgb, PixelTypes.Rgba32, JpegColorType.Rgb)]
[WithFile(TestImages.Jpeg.Baseline.Cmyk, PixelTypes.Rgba32, JpegColorType.Cmyk)]
public void Decode_DetectsCorrectColorType<TPixel>(TestImageProvider<TPixel> provider, JpegColorType expectedColorType)
where TPixel : unmanaged, IPixel<TPixel>
{

23
tests/ImageSharp.Tests/Formats/Jpg/JpegEncoderTests.cs
View File

@ -92,7 +92,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
[WithFile(TestImages.Jpeg.Baseline.Jpeg410, PixelTypes.Rgba32)]
[WithFile(TestImages.Jpeg.Baseline.Jpeg411, PixelTypes.Rgba32)]
[WithFile(TestImages.Jpeg.Baseline.Jpeg422, PixelTypes.Rgba32)]
public void Encode_WithUnsupportedColorType_FromInput_DefaultsToYCbCr420<TPixel>(TestImageProvider<TPixel> provider)
public void Encode_WithUnsupportedColorType_FromInputImage_DefaultsToYCbCr420<TPixel>(TestImageProvider<TPixel> provider)
where TPixel : unmanaged, IPixel<TPixel>
{
// arrange
@ -100,7 +100,10 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
using var memoryStream = new MemoryStream();
// act
input.Save(memoryStream, JpegEncoder);
input.Save(memoryStream, new JpegEncoder()
{
Quality = 75
});
// assert
memoryStream.Position = 0;
@ -110,12 +113,11 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
}
[Theory]
[WithFile(TestImages.Jpeg.Baseline.Jpeg444, PixelTypes.Rgba32, JpegColorType.Cmyk)]
[WithFile(TestImages.Jpeg.Baseline.Jpeg444, PixelTypes.Rgba32, JpegColorType.YCbCrRatio410)]
[WithFile(TestImages.Jpeg.Baseline.Jpeg444, PixelTypes.Rgba32, JpegColorType.YCbCrRatio411)]
[WithFile(TestImages.Jpeg.Baseline.Jpeg444, PixelTypes.Rgba32, JpegColorType.YCbCrRatio422)]
public void Encode_WithUnsupportedColorType_DefaultsToYCbCr420<TPixel>(TestImageProvider<TPixel> provider, JpegColorType colorType)
where TPixel : unmanaged, IPixel<TPixel>
[InlineData(JpegColorType.Cmyk)]
[InlineData(JpegColorType.YCbCrRatio410)]
[InlineData(JpegColorType.YCbCrRatio411)]
[InlineData(JpegColorType.YCbCrRatio422)]
public void Encode_WithUnsupportedColorType_DefaultsToYCbCr420(JpegColorType colorType)
{
// arrange
var jpegEncoder = new JpegEncoder() { ColorType = colorType };
@ -153,6 +155,11 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
}
}
[Theory]
[WithFile(TestImages.Png.CalliphoraPartial, nameof(BitsPerPixel_Quality), PixelTypes.Rgba32)]
public void EncodeBaseline_CalliphoraPartial<TPixel>(TestImageProvider<TPixel> provider, JpegColorType colorType, int quality)
where TPixel : unmanaged, IPixel<TPixel> => TestJpegEncoderCore(provider, colorType, quality);
[Theory]
[WithFile(TestImages.Png.CalliphoraPartial, nameof(BitsPerPixel_Quality), PixelTypes.Rgba32)]
[WithTestPatternImages(nameof(BitsPerPixel_Quality), 73, 71, PixelTypes.Rgba32)]

3
tests/ImageSharp.Tests/TestImages.cs
View File

@ -191,6 +191,9 @@ namespace SixLabors.ImageSharp.Tests
public const string Jpeg444 = "Jpg/baseline/jpeg444.jpg";
public const string Jpeg420Small = "Jpg/baseline/jpeg420small.jpg";
public const string JpegRgb = "Jpg/baseline/jpeg-rgb.jpg";
public const string Jpeg410 = "Jpg/baseline/jpeg410.jpg";
public const string Jpeg411 = "Jpg/baseline/jpeg411.jpg";
public const string Jpeg422 = "Jpg/baseline/jpeg422.jpg";
public const string Testorig420 = "Jpg/baseline/testorig.jpg";
public const string MultiScanBaselineCMYK = "Jpg/baseline/MultiScanBaselineCMYK.jpg";
public const string Ratio1x1 = "Jpg/baseline/ratio-1x1.jpg";

3
tests/Images/Input/Jpg/baseline/jpeg410.jpg
View File

@ -0,0 +1,3 @@
version https://git-lfs.github.com/spec/v1
oid sha256:318338c1a541227632a99cc47b04fc9f6d19c3e8300a76e71136edec2d17a5f5
size 9073

3
tests/Images/Input/Jpg/baseline/jpeg411.jpg
View File

@ -0,0 +1,3 @@
version https://git-lfs.github.com/spec/v1
oid sha256:70315936e36bb1edf38fc950b7b321f20be5a2592db59bfd28d79dbc391a5aaf
size 4465

3
tests/Images/Input/Jpg/baseline/jpeg422.jpg
View File

@ -0,0 +1,3 @@
version https://git-lfs.github.com/spec/v1
oid sha256:be21207ecb96bcb0925706649678c522c68bf08ee26e6e8878456f4f7772dd31
size 3951
Write Preview
Loading…
Cancel
Save